Audio Merging is an absolute mess

I'm convinced that I'm going to need whatever magical stardust Axel is using in his tutorial for merging audio, because out of three seperate computers with Hitfilm, none have pulled it off successfully.

Audio coming from android recordings, Zoom H6 or standard recorders in general ( yes, I really mean all the above) simply refuse to sync with the videos that come out of my GH4, my Sony FS700, and even more dismaying, my rebel T3i.

I debated the possibility that it might be a sound card issue, but from ALL THREE COMPUTERS?!

Incase you're wondering, the result after merging the audio is not even close. And these are just simple interview scenarios with an external audio recorder.

What's going on? This is one of Pro 2017's hyped features; why isn't there a fix yet?

"The key thing to watch for when recording separate audio is that both devices (audio and video) are started within 20 seconds of each other. The closer the start time of the two devices is, the better for syncing in post. If the gap is more than 20 seconds then HitFilm is likely to sync incorrectly, so in those4 cases, trim the excess off the beginning of which ever file starts first, before importing them into HitFilm, and you should get a nicely synced result."

I had tried many times with files whose beginning was less than 12 seconds apart. The shortest gap was 8 seconds: it didn't work (except in one case, when I recorded the sound with my Zoom H1).

On receiving the above answer, I tried trimming the files to bring the gap down to under 2 seconds, maybe less. It worked!

Just so you know, when using the H1 (set to a 96 000 Hz rate), sync-ing worked even thought the gap was around 9 seconds. But with the 48 000 Hz files from my phone, it didn't (the audio from my camera is 48 KHz), until I "removed" the gap. I don't know whether that's chance or not or if the more precise 96 KHz helps HitFilm do the job.

At any rate, since I find it easier to trim audio files than video ones, from now on, I'll make sure to start the sound recorder first, then the camera.